Electrochromism is a phenomenon displayed by some materials of reversibly changing optical properties by using bursts of charges to cause electrochemical redox (reduction and oxidation) reactions in electrochromic materials. The optical properties may include transmittance, reflectance, absorptance and emittance. In particular, electrochromic materials exhibit a reversible color change.
In an application of smart windows, electrochromic films are integrated with the glass window to become serviceable. Electric controller are used to control the electrochromic films integrated with glass windows (i.e., smart windows). The smart windows can be controlled locally and globally. In a building with many smart windows integrated with electrochromic films, a user may be able to control each single window independently as well as to control all the windows simultaneously by a central unit to overwrite the local control. To simplify installations of smart windows, a control unit could be integrated into a smart window as a self-contained and self-powered unit. In such control unit, no external power is needed. In addition, the installation can be further simplified by utilizing wireless charging.
In the present disclosure, we present different methods and systems for controlling state of electrochromic devices.